Luis Suarez's lawyer flew to Rio de Janeiro on Thursday morning to present his defence after the Uruguay striker appeared to bite a player during his team's 1-0 victory over Italy, leaving him facing a lengthy ban if found guilty by soccer's governing body.

The incident in Natal on Wednesday (AEST) has brought the ugly side of the game to the fore, marring a tournament that has been widely praised for its attacking football and major upsets.

Suarez, who has been banned from soccer twice previously for biting, had until 5:00pm local time (6:00am Thursday AEST) to present his case to FIFA.

"We're polishing off a defence argument," his lawyer Alejandro Balbi told local radio in Uruguay, where many people support the gifted frontman and feel he is being unfairly singled out by media in Europe.

"We don't have any doubts that this has happened because it's Suarez and secondly because Italy was eliminated," added Balbi, who is also a Uruguay FA board member. "There's a lot of pressure from England and Italy."

The incident came 10 minutes from time in Uruguay's Group D game against Italy, when television footage appeared to show Suarez sink his teeth into the shoulder of Italian defender Giorgio Chiellini, who has publicly accused him of biting.

We don't have any doubts that this has happened because it's Suarez and secondly because Italy was eliminated. There's a lot of pressure from England and Italy.

Alejandro Balbi

The Italians were still complaining when Uruguay's Diego Godin scored with an 81st-minute header to secure a win that sent the South Americans through to the last 16 and eliminated four-times champions Italy from the tournament.

Chiellini pulled down his shirt, and Reuters photographs showed what appeared to be bite marks on his shoulder.

The referee did not spot the incident during the match, but FIFA's rules allow the use of video or "any other evidence" to punish players retrospectively.

FIFA's disciplinary code sets a maximum ban of 24 matches or two years, but the longest suspension FIFA has imposed for an offence at a World Cup was eight games for Italy's Mauro Tassotti for breaking the nose of Spain's Luis Enrique in 1994.

Uruguay could potentially play four more games in the tournament, and it would be a surprise if Suarez were to be given a ban of a shorter duration if found guilty.

"I think it's very bad that it happened," he said. "He (Suarez) is an exceptional player, helps to give the World Cup more attention ... That was not the first bite. Other ones have happened."

Losing Suarez would be a huge blow to Uruguay, which relies heavily on the prolific Liverpool forward's attacking talent.

He scored both goals in the side's 2-1 win over England earlier in the tournament, and is widely considered the team's best player.

Suarez has denied biting Chiellini.

"Those are situations that happen on the pitch. We were both just there inside the area. He shoved me with his shoulder, and my eye got left like that also," he said on Tuesday, in reference to Chiellini's marks.

Controversy to hit Suarez in the pocket

Balbi, who is travelling to Rio de Janeiro with Uruguay FA boss Wilmar Valdez to present their case to FIFA, echoed those remarks.

He (Suarez) is an exceptional player, helps to give the World Cup more attention ... That was not the first bite. Other ones have happened.

Brazil sports minister Aldo Rebelo

"There is a possibility that they ban him, because there are precedents, but we're convinced that it was an absolutely casual play, because if Chiellini can show a scratch on one shoulder, Suarez can show a bruised and almost shut eye," Balbi said.

"We're going to use all the arguments possible so that Luis gets out in the best possible way."

Whatever the outcome of FIFA's investigation, the biting accusations could have an impact on Suarez's commercial value as one of the world's top strikers.

Poker brand 888 said on Wednesday it was "seriously reviewing" its sponsorship agreement with him after Suarez became one of the online gambling company's brand ambassadors last month.

Suarez has an endorsement deal with German sportswear company Adidas, and he has also been advertising the Beats headphones worn by many top players.